Check eBay and craigslist. Now, of course, is the worst time of the year to be shopping for a cross bike, and you're doubly cursed by your height.
One possible strategy would be to get a cross frameset (either used or new) and buy a used road bike for parts (or maybe you have a road bike lying around). Add knobby tires and cantilever brakes et voila.
Another possibility, get a lower-end new cross bike from one of the major makers. The frame will probably be fine, you can upgrade wheels and/or components in the future as you wish, or you can sell it next year to start financing the "serious" bike. If you're not afraid of steel, Bianchi Volpe might be a good choice for this sort of thing. The largest size is 61, but that's a semi-compact frame so probably works out to 62 or 63 in traditional sizing -- but don't take my word for it. Surly Cross Check goes up to 62, and does come in a built-up version.
My #1 recommendation is: Get something (anything) and go out and race!